Abbott & Costello 1942 Knights in Shining Armor with Merle Oberon

Abbott and Costello were an American comedy duo composed of comedians Bud Abbott and Lou Costello, whose work in radio, film, and television made them the most popular comedy team of the 1940s and early 1950s, and the highest-paid entertainers in the world during World War II.
Their patter routine "Who's on First?" is considered one of the best-known comedy routines of all time. Their popularity waned in the early 1950s due to overexposure and changing tastes in comedy, and their film and television contracts lapsed. The partnership ended soon afterwards.
Radio
With Carmen Miranda, The Streets of Paris, in 1939.
The team's first known radio broadcast was on The Kate Smith Hour on February 3, 1938. At first, the similarities between their voices made it difficult for radio listeners (as opposed to stage audiences) to tell them apart during their rapid-fire repartee. As a result, Costello affected a high-pitched, childish voice. "Who's on First?" was first performed for a national radio audience the following month. They performed on the program as regulars for two years, while also landing roles in a Broadway revue, The Streets of Paris, in 1939.

Abbott and Costello on radio
After debuting their own program, The Abbott and Costello Show, as Fred Allen's summer replacement in 1940, Abbott and Costello joined Edgar Bergen and Charlie McCarthy on The Chase and Sanborn Hour in 1941. Two of their films (Buck Privates and Hold That Ghost) were adapted for Lux Radio Theater that year. Their program returned in its own weekly time slot starting on October 8, 1942, with Camel cigarettes as sponsor.

The Abbott and Costello Show mixed comedy with musical interludes (by vocalists such as Connie Haines, Ashley Eustis, the Delta Rhythm Boys, Skinnay Ennis, Marilyn Maxwell and the Les Baxter Singers).

Among the show's regular and semi-regular performers were Joe Kirk (Costello's brother-in-law) as the excitable Sicilian immigrant Mr. Bacciagalupe, Artie Auerbach as Mr. Kitzel, Elvia Allman, Iris Adrian, Mel Blanc, Wally Brown, Sharon Douglas, Verna Felton, Sidney Fields, Frank Nelson, Martha Wentworth and Benay Venuta. Guest stars included Cary Grant, Frank Sinatra, The Andrews Sisters and Lucille Ball.

Ken Niles was the show's longtime announcer, doubling as an exasperated foil to Costello, who routinely insulted his on-air wife (played by Elvia Allman). Niles was succeeded by Michael Roy, alternating over the years with Frank Bingman and Jim Doyle.

The show went through several orchestras, including those of Ennis, Charles Hoff, Matty Matlock, Matty Malneck, Jack Meakin, Will Osborne, Fred Rich, Leith Stevens and Peter van Steeden.

The show's writers included Howard Harris, Hal Fimberg, Parke Levy, Don Prindle, Eddie Cherkose (later known as Eddie Maxwell), Leonard B. Stern, Martin Ragaway, Paul Conlan and Eddie Forman, as well as producer Martin Gosch. Sound effects were handled primarily by Floyd Caton.

In 1947 the show moved to ABC (the former NBC Blue Network). During their time on ABC the duo also hosted a 30-minute children's radio program (The Abbott and Costello Children's Show) on Saturday mornings. The program featured child vocalist Anna Mae Slaughter and child announcer Johnny McGovern. It finished its run in 1949.